/* this class serves to privide a implementation abstract of "Display" (An Interface).
 * so it at the top of implementation layer, providing a structure for implement class
*/
#ifndef DISPLAY_IMPL_H
#define DISPLAY_IMPL_H

namespace ImplLayer
{
class DisplayImpl
{
  public:
    virtual void rawOpen() = 0;
    virtual void rawPrint() = 0;
    virtual void rawClose() = 0;
};
}; // namespace ImplLayer

#endif
